I know that hn is heavily populated by people from the USA, that the author is dutch but a non-english language would be... every other language beside English.
Commenting on the actual text, his solution for the cedilla is awkward and is one of the first things I disable on any computer, because it is a extremely common letter in portuguese.
In particular, for anybody wondering, the non-english languages they refer to (wrt to the layout they talk about) are
> English (of course), Danish, Dutch, Finnish, French, German, Italian, Norwegian, Portuguese, Spanish and Swedish
so basically all using some variation of the latin alphabet.
I agree that typing curly braces and square brackets on non English keyboards suck, but typing non English languages on an English keyboard sucks too. I made the opposite of your decision: I brought a laptop with my national keyboard and I switch to US layout when programming. That has had a curious effect on me: as my editor and my terminals have black backgrounds and everything else has a white one, something in my brain makes my fingers reach for keys according to the color of the background. I make many mistakes when I attempt to program in a white window (eg: type in gedit) or write in my language in a black one (eg: an md file in terminal.)